1. Field of the Invention
The present invention relates to a magneto-resistance element such as a magneto-resistance sensor, a magneto-resistance head, etc.
2. Prior Art
Development of magneto-resistance sensors (hereinafter called MR sensor) and magneto-resistance heads (hereinafter called MR head) utilizing magneto-resistance elements in which mainly Ni.sub.0.8 Fe.sub.0.2 permalloy or Ni.sub.0.8 C.sub.0.2 alloy film is used as magnetic material has been promoted. In the case of these magneto-resistance effect materials, magneto-resistance variation rate (hereinafter called .DELTA.R/R) is about 2.5% and when it is actually used as the sensor or head, the magneto-resistance effect material is usually patterned as shown in FIG. 1 (b) and the element is so designed that the direction of electric current to run through the magneto-resistance effect material and the direction of magnetic field to be sensed make roughly right angle. The reason for it is that when the direction of electric current and the direction of magnetic field are in parallel, the magneto-resistance effect material practically generates no magneto-resistance variation rate (.DELTA.R/R). In order to make the magneto-resistance element more sensitive, it is desired that the magneto-resistance material have a larger magneto-resistance variation rate (.DELTA.R/R).
In recent years it has been discovered that a large magneto-resistance effect is obtained with [Fe/Cr], [Co/Ru] artificial lattice membrane which forms anti-ferrogmagnetic bonding via a metallic non-magnetic thin film made of Cr, Ru, etc. (Physical Review Letter Vol. 61, P2472, 1988; ditto Vol. 64, P2304, 1990). A large magneto-resistance effect was also found with [Ni-Fe/Cu/Co] artificial lattice membrane using magnetic thin film Ni-Fe and Co separated by metallic non-magnetic thin Cu film which is not making magnetic bonding and they obtained the film with .DELTA.R/R of about 10% at room temperature and impression magnetic field of 3K Oe (Journal of Physical Society of Japan Vol. 50, P3061, 1990). A large magneto-resistance effect was further discovered with [Ni-Fe-Co/Cu/Co], [Ni-Fe-Co/Cu] artificial lattice films using a Ni-Fe-Cu/Co magnetic thin film which makes an anti-ferromagnetic bonding via Cu and they obtained a film with .DELTA.R/R of about 15% at room temperature and impression magnetic field of 0.5 KOe (Technical Research Report MR91-9 of the Society of Electronic Data Communication). However even when such artificial metallic lattice film is patterned and the element is so constructed as the direction of electric current to run through the magneto-resistance effect material and the direction of magnetic field to be sensed should make roughly a right angle as in the case of the conventional magneto-resistance material, the magnetic sensor or magnetic head with preferred characteristics is not obtained.